WO2007009139A1

WO2007009139A1 - Exhaust gas line of an internal combustion engine

Info

Publication number: WO2007009139A1
Application number: PCT/AT2006/000285
Authority: WO
Inventors: Christof Knollmayr; Andreas Zurk; Kurt Prevedel; Josef Wolkerstorfer; Paul Kapus
Original assignee: Avl List Gmbh
Priority date: 2005-07-19
Filing date: 2006-07-04
Publication date: 2007-01-25
Also published as: DE112006001805A5; US20140130769A1; US20090133390A1; US8555627B2

Abstract

The invention relates to an exhaust gas line (1) of an internal combustion engine, comprising at least one catalyser (2) which is provided with at least one catalyser support (4) which is arranged in the housing (3) and which comprises at least one first and one second parallel area (5, 6) which can be cross-flown. The current through at least one area can be deactivated by means of a circuit device (8) which is arranged in the exhaust gas line (1). In order to start the catalyser, which is compact and simple to use, in a rapid manner, the areas (5, 6) of the catalyser support (4) comprise different physical and/ or chemical properties in relation to the response behaviour, the permeability, the catalytic activity and/or the thermal inertia.

Description

Exhaust line of an internal combustion engine

The invention relates to an exhaust system of an internal combustion engine, with at least one catalyst having at least one catalyst support arranged in a housing, which has at least a first and a second parallel-flow region, wherein the flow can be deactivated by at least one region by means of a switching device arranged in the exhaust system.

Furthermore, the invention relates to an internal combustion engine with an exhaust system and with at least one water injection device for the injection of water into the exhaust system.

Furthermore, the invention relates to a cylinder head for a liquid-cooled internal combustion engine with a liquid-cooled exhaust manifold formed integrally with the cylinder head, wherein the cylinder head has at least one first cooling space.

From DE 36 29 945 Al an exhaust system with a catalyst with arranged in a housing catalyst carriers is known, wherein the catalyst carriers are arranged concentrically to each other and both are parallel to each other. In this case, the exhaust gas stream downstream of the catalyst carrier is divided into two exhaust gas channels. By at least one switching device arranged in an exhaust gas channel, one of the two catalyst carriers can be deactivated. As a result, a mutual influencing of the temperature of the catalyst carriers can be achieved so that the most favorable temperature range for the aftertreatment of the exhaust gases can be reached more quickly or kept more securely.

DE 102 01 042 A1 discloses an exhaust system for an internal combustion engine having a catalytic exhaust gas converter with a housing, a catalyst support supported in the housing and an inlet pipe. In the inlet pipe, a swirl generator is arranged, which leaves free a central flow path. The catalyst support has an inner area and an outer area, viewed in the axial direction of view, wherein the cell density of the flow channels in the inner area is greater than in the outer area and / or the inner area is designed with greater catalyst activity than the outer area. An active switching possibility between the two areas is not provided. DE 199 38 038 A1 describes an exhaust gas treatment device with varying cell density, wherein the densities of the cell groups are arranged so that a uniform flow through the entire substrate is promoted.

Furthermore, from DE 92 01 320 Ul a catalyst device for internal combustion engines is known, in which the housing surrounding the catalyst substrate at least two connectable to the internal combustion engine exhaust inlet pipes and at least two gas outlet pipes are connected, the cross-sectional areas on the inlet and outlet side respectively different areas of the associated Face substrate faces. By means of shut-off devices arranged on the inlet and outlet side, an operation-dependent variation of the exhaust gas flow guidance through the catalyst substrate with and without multiple flow diversion can be carried out. This should be ensured at all possible operating conditions of the internal combustion engine, a sufficient exhaust gas cleaning effect. Areas with different physical and / or chemical properties with regard to the response, the permeability, the catalytic activity and / or the thermal inertia are not provided.

The design of the cross-section and the permeability of the catalyst represents a compromise between sufficient surface loaded with noble metal to ensure a rapid light-off during cold start and low pressure drop at rated power. The first is in highly effective catalytic coatings, given a space, high cell densities, The latter, in contrast, benefits from low cell densities.

This conflict of objectives is in the prior art, for example, by connecting a first catalyst support with a high cell density and short length and a second catalyst support with rather lower cell density, but longer and larger cross-section, which are separated in the exhaust line separately, or else in a housing can, solved. Another embodiment, which is more compromised in its function than the first-mentioned embodiment, uses a single catalyst support which is provided with a particularly highly effective catalytic coating on its gas inlet side over a certain length, but with a comparatively normal coating over the remaining length, so that one of a zone coating speaks. Other with respect to the function certainly advantageous but large construction cost demanding versions, such as cascade switchable acted catalyst support, find due to their complexity no use. Electrically heatable catalyst carriers for rapid light-off which, for this reason, could be carried out in accordance with the requirements at rated power greater and with lower pressure losses, necessary as a substrate metal and a corresponding electrical supply and are currently hardly used because of high costs.

Future gasoline engine concepts, however, which can be expected by the multi-stage turbocharging a doubling of the usual performance today with corresponding extreme spreads of the lowest and maximum exhaust gas flow rates and also rely on low exhaust back pressures at full load and rated power, but with the known structurally simple solutions difficult to use. Structurally complex solutions, such as cascade arrangements, will encounter building space limits. In addition, the heating behavior is additionally impaired by the at least significantly increasing exhaust-wetted wall surfaces with multistage turbocharging concepts.

Compliance with component temperature limits in the catalytic converter and / or turbocharger is currently ensured by utilizing the heat of vaporization of additionally injected fuel. Consequently, rich mixture is present in considerable areas of the operating map, which is largely responsible for the distinct difference between cycle consumption and practical consumption compared to the diesel engine. This problem is intensified with increasing specific power and represents a conflict of objectives for highly charged down-sizing engine concepts whose purpose is indeed a reduction in fuel consumption in real vehicle operation.

Especially turbocharged engines with stoichiometric mixture, even at full load and rated power, can be operated with consumption improvements at rated power between 15% and 30% and absolute values around 260 g / kWh if measures other than enrichment are used for cooling purposes. In real driving, the savings can range from 5% to 20%, depending on the driving profile, engine-vehicle combination and fuel quality.

At present there are two known ways of achieving the mentioned improvement in consumption:

1) Use of high temperature resistant materials for exhaust manifold, turbine and catalyst to reduce the Anfettungsbedarf by a shift from the typical turbine inlet temperatures of 950 ⁰ C today to 1000 ⁰ C to 1050 ⁰ C. In addition to significantly higher costs and increasing problems with, for example, catalyst aging, thermomechanical problems and heat radiation, the potential is limited here. Especially when operating with unfavorable hot conditions, as well as cheaper fuels of lower octane number, the temperature limit must again be met by increased enrichment.

2) Higher potential than an increase in the temperature limit, the involvement of the exhaust gas piping before the turbine, for example, in a water-cooled cylinder head, as described for example in the Austrian patent application A 1216/2005. Here, the gas cooling is not directly, but indirectly by the heat transfer to external surfaces. By appropriate design, a wider range of action than with the temperature limit increase is possible and the need for additional enrichment potentially lower. By a high system integration, a relatively low production costs can be achieved. However, the heat is dissipated in the cooling water circuit and at speeds below the maximum torque is a loss of torque in turbo engines to consider, since a minimum flow of the water jacket and thus cooling to limit the water boiling is to be maintained, resulting in lower energy content of the exhaust gas ,

From WO 98/10185 Al it is known to inject water for NO _x - reduction in front of a compressor in an intake system of an internal combustion engine. A similar system is known from JP 56-083516 A.

US 5,131,229 A discloses a turbo-internal combustion engine with external exhaust gas recirculation, wherein water is injected into the exhaust gas flow for the IM O _x reduction. The water is taken from a tank, which can be heated to protect against freezing.

US 6,151,892 A1 discloses an internal combustion engine with programmed water injection into the exhaust system to change the gas dynamics to better match the cylinder scavenging. As a result, the vibration length is influenced by changing the exhaust gas temperature.

Furthermore, an exhaust gas system for an internal combustion engine is known from US Pat. No. 6,357,227 B1, wherein a condensate collector is provided, which is arranged upstream of a device for purifying the exhaust gas and is fluidically connected to the exhaust gas line. The condensate collector is connected to a water reservoir, which is fluidly connected to a storage for reducing agent for a catalyst. The water, which is guided in the exhaust pipe, can condense before entering the exhaust gas aftertreatment device. The disadvantage is that for the condensation device water from the untreated exhaust gases upstream of the exhaust aftertreatment is removed, whereby the condensation system is exposed to heavy pollution. A permanent function of the system is therefore not guaranteed.

From US 2005/0087154 Al it is known to carry out the exhaust manifold integrally with the cylinder head. The main cooling space formed by an upper and a lower partial cooling space is thermally connected to the exhaust manifold. A separate control of the cooling of the exhaust manifold is not provided.

It is the object of the present invention to solve this conflict of objectives with comparatively little additional effort and, if possible, to enable optimal exhaust gas purification in each engine operating region.

It is also an object of the invention to substantially reduce fuel consumption.

Furthermore, it is an object of the invention to be able to adjust the cooling of the exhaust manifold independently of the cooling space of the cylinder head.

According to the invention, this is achieved in that the regions of the catalyst support have different physical and / or chemical properties with regard to the response, the permeability, the catalytic activity and / or the thermal inertia. It can be provided that the two areas have different cell densities and / or that the areas have different coatings.

The two areas can be arranged coaxially with each other or seen in the longitudinal direction side by side.

The cross-sectional areas of the two areas are different. The larger area is dimensioned sufficiently large for the nominal power requirement, the area with the small cross-sectional area is reserved for the cold start.

The catalyst support is preferably formed in one piece and consists of a single monolith.

The switching device may be formed by a simple switching flap, but it is also possible that the switching device is part of the wastegate of a arranged in the exhaust line exhaust gas turbocharger.

In principle, it is possible to arrange the switching device downstream or upstream of the catalyst carrier in the exhaust system. Between the switching device and the catalyst carrier, a dividing wall is arranged along the exhaust gas flow, which allows a flow divided in accordance with the regions between the catalyst carrier and the switching device.

In order to compensate for high temperature gradients between the two regions, it is advantageous if at least one leakage opening is arranged in the region of the switching device and / or in the region of the partition wall, which measures a predefined exhaust gas quantity to the deactivated region. It can be provided that the leakage opening is formed by at least one opening, a corrugation or a perforation of the partition wall, preferably in a wall region adjoining the catalyst support.

In a particularly preferred embodiment variant of the invention, provision is made for a first flow deflection device to be arranged in the region of the outlet from the second region of the catalyst support, which recirculates at least part of the exhaust gas leaving the second region through a first sector of the first region, so that the Exhaust gas meandering through the exhaust catalyst flows. Thus, the first region of the catalyst support is brought to start temperature. This results in an extensive use of the residual heat, or the exothermic reactions beginning, which also contributes to bring the catalyst quickly to operating temperature.

The areas and / or sectors can be arranged side by side, viewed in the longitudinal direction, but also a coaxial arrangement with respect to one another is conceivable.

The cross-sectional areas of the regions and / or the sectors may be different. The larger area is dimensioned sufficiently large for the nominal power requirement, the area with the smaller cross-sectional area is reserved for the cold start.

It is preferably provided that in the region of the entry of the first region of the catalyst support, a second flow deflection device is arranged for the exiting from the first sector of the first region of the catalyst carrier exhaust gas, which supplies the recirculated exhaust gas to a second sector of the first region. Due to the deflection, the exhaust gas during the warm-up phase can be guided meandering through the catalyst carrier, which allows rapid heating of the catalytic converter to the response temperature. It is particularly advantageous if the first flow deflection device is formed by a first switching device which can be switched between at least two positions, wherein in a first position the exhaust gas emerging from the second region of the catalyst carrier can be traced in the direction of the first sector of the first region. Preferably, it is provided that between the catalyst carrier and the first switching device is arranged a substantially longitudinally aligned flow of the first partition, wherein one end of the partition wall downstream of the first region is arranged and defines the boundary between the first and second sector of the first region.

Furthermore, it can be provided that the second flow deflection device is formed by a second switching device, which is switchable at least between two positions, wherein in a first position, the recirculated through the first sector of the first region exhaust gas is deflected in the direction of a second sector of the first region, wherein between the second switching device and the catalyst carrier, a longitudinally oriented flow dividing wall is arranged, which divides the exhaust gas flow - with the second switching device open - into a first region leading to the first region and a second region leading to the region.

The flow cross section of the second sector of the first region of the catalyst carrier corresponds at least to the flow cross section of the first sector of the first region of the catalyst carrier.

In a simple embodiment of the invention, it is provided that the first and / or second switching device is formed by a switching flap. But it is also possible that at least one switching device is functionally part of a wastegate of an exhaust gas turbocharger arranged in the exhaust system. It when the first and the second switching device are simultaneously actuated via at least one actuator is particularly advantageous.

To reduce the fuel consumption is provided that the water injection device upstream of an exhaust aftertreatment device, preferably upstream of a turbine of an exhaust gas turbocharger, opens into the exhaust system. Through the air-distributed injection and evaporation of water or aqueous solutions into the outlet branch, the need for a mixture enrichment can be largely prevented.

The water can be from direct fueling, by condensation of engine exhaust gases (about 1 kg of water per kg of burned fuel) in a suitable condensation system, as well as by using condensates on the vehicle side Systems, for example, the air conditioning, related. In order to collect continuously accumulating small amounts of condensate and to keep the heat exchange surfaces necessary for condensation small, a reservoir is provided, the size of which is designed according to the operating experience so that a Leerfalls does not occur. Since the water has about five times the heat of evaporation of fuel, the volumetric demand for water or condensate for exhaust gas cooling is comparatively low. The savings in average fuel consumption through the absence of greasing can be of the order of 5% to 20% depending on the driving profile, engine-vehicle combination and fuel quality. For example, per liter of spent water about 5 liters of fuel can be saved.

It can be provided that the condensation system has an exhaust gas condensation device which can be connected to the exhaust gas line via an exhaust gas removal line. Alternatively or additionally, it is possible that the condensation system comprises an air condensation device, wherein preferably the air condensation system is part of an air conditioning system.

An advantageous embodiment of the invention provides that the condensation system has a condenser with filter and reservoir, in which the condensate inlet of the exhaust gas condensing device and / or the condensation feed an air condensation device, preferably an air conditioner, opens, preferably wherein the water injection system has a flow control device, which in the water injection system is arranged downstream of a feed pump.

The service life of the condensation system can be substantially increased if the exhaust gas extraction line branches off from the exhaust gas line downstream of the exhaust gas aftertreatment device. In order to ensure winter-safe operation, it is advantageous if the water injection system either has a frost protection device or is designed such that the correct function becomes available again with increasing heating of the engine. A frost-related failure of the function can be detected by the engine control, which if necessary, the known mixture enrichment can be used to comply with limit temperatures until the system is functional again. The same applies to the case of too little condensate supply after, for example, a long interruption of operation of a vehicle.

After passing through the exhaust gas condensing device, the exhaust gas branched off via the exhaust gas removal line is fed to an intake branch of the internal combustion engine via an exhaust gas recirculation line adjoining the condensation system, wherein a non-return valve or a control valve is provided in the exhaust gas recirculation line. valve can be arranged. In order to enable a recovery of water from the exhaust gas with recirculation of exhaust gas into the intake line even in the charged partial load operation, it is advantageous if the exhaust gas recirculation line opens into the intake line upstream of a compressor.

In order to adjust the cooling of the exhaust manifold, independently of the cooling space of the cylinder head, it is advantageous if the region of the exhaust manifold is at least partially surrounded by a second cooling space which is at least partially separated from the first cooling space, wherein preferably the coolant flow through the second Refrigerator is separated from the coolant flow through the first cooling chamber adjustable. At least one separate coolant inlet, preferably emanating from the cylinder head sealing surface, which is flow-connectable to a cooling jacket of the cylinder block, is present in the second cooling space.

The water inlet into the second cold room can be done as a separate water inlet from the outside or through openings in the fire deck. In the latter embodiment, throttle openings in the cylinder head gasket can allow additional tuning of the coolant quantity and the uniform distribution. The coolant inlet or coolant outlet of the additional second cooling space may contain a thermostat or a preferably electrical switching valve for controlling the additional water circuit in the engine heating phase.

The invention will be explained in more detail below with reference to FIGS. They show schematically:

Figure 1 shows a part of a Abgasstranges invention in a longitudinal section.

Figure 2 shows the exhaust line in a section along the line II-II in Fig. 1.

3 shows the exhaust gas line in a section along the line III-III in Fig. 1.

4 shows a catalyst in a longitudinal section;

5 shows a catalyst in a cross section in a first embodiment;

6 shows a catalyst in a cross section in a second embodiment;

7 shows a catalyst in a cross section in a third embodiment; 8 shows a catalyst in a cross section in a fourth embodiment;

9 shows a catalyst in a cross section in a fifth embodiment;

10 shows a catalytic converter in a cross section in a sixth embodiment;

11 shows a part of an exhaust line according to the invention in a further embodiment in a longitudinal section during a warm-up phase;

Fig. 12 the same part in the warm operating condition;

13 shows an internal combustion engine according to the invention in a first embodiment;

14 shows an internal combustion engine according to the invention in a second embodiment variant;

15 shows an internal combustion engine according to the invention in a third embodiment s variant;

16 is a characteristic diagram of an Otto internal combustion engine;

FIG. 17 shows a cylinder head according to the invention in a section according to the line XVII-XVII in FIG. 18; FIG.

FIG. 18 shows the cylinder head in a fire deck side view; FIG. and

19 shows the cylinder head in a section along the line XIX-XIX in Fig. 17th

In the exhaust line 1, an exhaust gas catalyst 2 is provided with a catalyst carrier 4 arranged in a housing 3 and formed by a monolith, which has a first region 5 and a second region 6 with different properties with regard to the light-off behavior, the permeability, the catalytic activity or the like. The different properties are brought about by different cell densities and / or different coatings of the catalyst carrier 4 in the two regions 5, 6. Near the inlet region or the outlet region into the catalyst carrier 4, a switching device 8 formed by a flap 7 is arranged in the exhaust gas line 1. Between the switching device 8 and the catalyst carrier 4 is a partition wall 9 formed by a sheet metal aligned in the direction of the exhaust gas flow, which divides the exhaust gas flow between the catalyst carrier 4 and the switching device 8 into two flow paths corresponding to the areas 5, .6.

In order to reduce high temperature gradients of the two areas 5, 6, the partition wall 9 has leakage openings 10, which allow a minimum flow through the deactivated area 5 when the flap 7 is closed. The minimum flow can be formed by openings, corrugations, perforations or the like in the partition wall 9.

FIGS. 4 to 10 show various constructional arrangement possibilities of the two regions 5, 6. In FIG. 5, the regions 5, 6 have the same cell density but different coating. In the remaining FIGS. 6 to 10, the regions 5, 6 are designed with different cell densities. In addition to a circular cross-sectional shape, an oval shape is also possible, as shown in FIGS. 9 to 10. The smaller area 6 can be arranged laterally in the area of an outer wall or concentrically to the larger area 5.

The flap 7 is closed during cold start. After the so-called light-off, the flap 7 is increasingly opened by the motor control to maintain the catalytic reaction during the heating of the remaining large area 5 of the monolith. After starting the entire catalyst 2, the flap 7 is completely pivoted out of the exhaust stream. In applications with operating extremely large spreads of the exhaust gas volume flow outgoing the catalyst 2, for example, at idle, by vorhaltenes closing the flap 7 can be prevented. The flap 7 may be mounted in a comparable form at the outlet nozzle. In order to avoid uncontrollable large dimensions, thermal loads and actuating forces of the flap 7, this is in a region of relatively small diameter, ie arranged at the beginning of the inlet housing or at the end of Ausströmgehäuses, wherein the partition wall 9, the gas guide until just at the entrance to the Areas 5, 6 of the catalyst carrier 4 worried. The design of the partition wall 9 can also influence the flow of the catalyst support can be taken.

The region 6 may be provided over its length for a rapid light-off with a particularly highly effective catalytic coating. In contrast to known coatings, the zone coating of the catalyst support 4 is not along its flow axis, but in the radial direction parallel to the flow axis, corresponding to the intended size of the provided by the flap 7 for the cold run for applying circular segment or other surface portion. Furthermore, the ceramic substrate of the catalyst support 4 can be performed in the region 6 of the monolith according to the production in the extrusion process with higher cell density, to obtain advantageously large active areas with low thermal inertia. This measure can also be carried out in combination with the zone coating described above.

FIGS. 11 and 12 show an exhaust gas line 101 in which an exhaust gas catalytic converter 102 is provided with a catalyst carrier 104 arranged in a housing 103 and formed by a monolith, which has a first area 105 and a second area 106 with different properties if required with regard to light-emitting behavior, permeability, catalytic activity or the like. The different properties are brought about by different cell densities and / or different coatings of the catalyst carrier 104 in the regions 105, 106. Near the inlet region and the outlet region in or out of the catalyst carrier 104, switching devices 108a, 108b formed in the exhaust gas line 101 by flaps 107a, 107b are arranged. Between the first switching device and the catalyst support 104, a first partition wall 109a formed, for example, by a sheet, is aligned in the direction of the exhaust gas flow. Between the second switching device 108b and the catalyst carrier 104, a second partition wall 109b is also provided, which is arranged substantially along the exhaust gas flow S. The second partition wall 109b divides the exhaust gas flow into two flow paths corresponding to the regions 105, 106 with the second flap 107b open. The first switching device 108a forms, together with the first partition wall 109a, a first deflecting device purple for exhaust gas exiting from the second region 106 of the catalyst carrier 104. The end 109a 'of the second partition wall 109a is arranged in the region of the outlet of the first region 105, so that the exhaust gas flow deflected according to the arrow S is returned in a first sector 105a of the first region 105. By choosing the arrangement of the end 109a 'of the first partition wall 109a, the ratio of the flow cross sections of the first sector 105a to the second sector 105b can be set, wherein the flow cross section of the second sector 105b is greater than or equal to the flow cross section of the first sector 105a. The recirculated exhaust gas, after flowing through the first sector 105a of the first region 105 through the second deflecting device 111b formed by the second switching device 8b and the second dividing wall 9b, is redirected again and fed to a second sector 105b of the first region 105 of the catalyst carrier 104, so that the exhaust gas meandering through the catalyst carrier 104 in three passes. The switching devices 108a, 108b can be closed or opened synchronously via an adjusting device 112. The regions 105, 106 may have various structural shapes and / or coatings. It is conceivable that the regions 105, 106 are designed with the same cell density but different coatings. Likewise, it is possible to execute the regions 105, 106 with different cell densities. In addition to a circular cross-sectional shape and an oval shape is possible. The smaller area 106 can be arranged laterally in the region of an outer wall of the housing 103, or also concentrically with the larger area 105.

The flaps 107a, 107b are closed at cold start, as shown in Fig. 11. The exhaust gas flows through the second region 106 in accordance with the arrow S in FIG. 11, is deflected by the deflecting device 1 a and returned through a first sector 105 a of the first region 105 of the catalyst carrier 104. Thereafter, the exhaust gas is again deflected by the second deflecting device 111b and flows through the second sector 105b of the first region 105. This meandering flow through the catalyst carrier 104 achieves a particularly rapid heating of the exhaust gas catalytic converter 102 which is uniform over the cross section. After starting the entire catalytic converter 102, the flaps 107a, 107b are completely pivoted out of the exhaust gas flow, as shown in Fig. 12.

Again, the region 106 may be provided over its length for a rapid light-off with a particularly highly effective catalytic coating. In contrast to known coatings, the zone coating of the catalyst support is not along its flow axis, but in the radial direction parallel to the flow axis, according to the intended size of the provided by the flaps 107 a, 107 b for the cold run for applying circular segment or other surface section.

Furthermore, the ceramic substrate of the catalyst support 104 in the region 106 of the monolith can be carried out in accordance with the production in the extrusion process with higher cell density in order to advantageously achieve large active areas with low thermal inertia. This measure can also be carried out in combination with the zone coating described above.

FIG. 13 shows an internal combustion engine 201 with an inlet line 202 and an exhaust line 203. Reference symbol 204b denotes a turbine of an exhaust gas turbocharger 204 arranged in the exhaust line 203. Via a water injection device 205 of a water injection system 206, water can be injected into the exhaust line 203 upstream of the turbine 204b and upstream of an exhaust gas aftertreatment device 207. The water injection system 206 further includes a feed pump 208 and a flow regulator 209 for metering the amount of water. The feed pump 208 and the quantity control device 209 are controlled by a control unit ECU. The injection is preferably carried out in the exhaust ports of the internal combustion engine 201, immediately after the exhaust valves. The water injection device 205 is designed so that a largely air-distributed injection of the water is ensured. This can be done either via atomizing nozzles or via individual atomizer valve units. The nozzles of the water injection device 205 must be arranged in a cooled environment, so that no vapor bubble formation takes place in the nozzle and within the distribution lines.

The water can be obtained on board the vehicle through a condensation system 210 with a condenser 210 a, a filter, not shown, and a reservoir 211. The condensate inlet 212 of an exhaust gas condensation device and / or the condensate inlet 213 of an air condensation device, for example an air conditioning system, opens into the reservoir 211 of the condensation system 210.

The injection of water takes place against the exhaust gas pressure, therefore injection pressures of about 2 bar to 5 bar are required.

FIG. 14 shows an embodiment variant of a water injection system 206 and a condensation system 210, wherein exhaust gas is taken from the exhaust line 203 downstream of the exhaust gas aftertreatment device 207 formed, for example, by a catalyst and downstream of the muffler 215 via an exhaust gas removal line 214 and fed to the condensation system 210. The fact that the exhaust gas is removed at the end of the exhaust line 203, there is already a significant temperature reduction. In the condensation system 210, with the condensation of the exhaust gas or the air using the low temperatures of an air conditioner, recovery of the water collected in a reservoir 211 occurs. The dry cooled gas is supplied downstream of the throttle 216 to the intake manifold 202 via an exhaust gas recirculation line 214a in which a check valve 217 is disposed. Thus, cooled recirculated exhaust gas is available in the intake manifold 202. The intake manifold pressures prevailing at partial load enable the exhaust gas to be condensed. At higher boost pressure closes the check valve 217, the exhaust gas backflow and thus the condensation is omitted. The exhaust gas condensation is thus carried out only at throttled part-load operation, where favorable for the condensation favorable low exhaust gas temperatures and with small condensation systems 210 Auslangen can be found. In order to be able to serve the demand, which exists exclusively at higher engine loads, sufficient, the reservoir 211 is required, which at least the hourly demand for condensate for a fumigant Should include rated power operation. In addition to the condensation from the exhaust gas, condensate accumulating from other vehicle systems, in particular the heat exchanger of the air conditioning system, can also be used and collected in the reservoir 211.

As shown in FIG. 15, additional amounts of condensate can be obtained from clean, cooled, and controlled volume EGR operation, even at boosted part loads, by controlling exhaust gas to the intake manifold 202 via a control valve 218 controlled by the control unit ECU upstream of the compressor 204a of the exhaust turbocharger 204 is supplied via an exhaust gas recirculation line 214b. The operation of the condensation system 210 is effected by the pressure difference between the entry into the compressor 204a and the exhaust gas pressure downstream of the exhaust aftertreatment device 207 with the interposition of the control valve 218th

In order to enable winter-proof operation, the water injection system 206 can be made heatable.

16 shows an engine map of an Otto internal combustion engine, wherein the mean pressure p _m is plotted against the rotational speed n. A denotes the lower part load range, B the middle part load range and C the upper part load range. Especially in the middle and upper part load range B, C occur considerable consumption disadvantages compared with stoichiometric operation, since in these operating ranges enrichment for compliance with exhaust gas temperature limits is essential. By water injection in the areas B, C can be avoided enrichment and thus consumption disadvantages can be prevented. ,

FIGS. 17 and 18 show a cylinder head 301 for an internal combustion engine having two intake valves and two exhaust valves per cylinder. With reference numeral 302, the inlet channels, designated by reference numeral 303, the outlet channels. The cylinder head 301 has a main cooling jacket forming the first cooling chamber 304 for cooling thermally critical adjacent to the combustion chamber areas, which is connectable via first inlet openings 305, 306 in the fire deck 307 with a cooling jacket of a cylinder block not shown.

Integral with the cylinder head 301, an exhaust manifold 308 is formed, which is at least partially surrounded by a second cooling chamber 309. The second cooling space 309 is substantially separated from the first cooling space 304 and has separate inlets 310 and outlets 312 for the coolant. In the embodiment shown in the figures, the second cooling space 309 connectable via separate second inlet openings 311 in the cylinder head sealing surface 307a of the fire deck 307 with the cooling jacket of the cylinder block.

Through the separate second cooling chamber 309 for the region of the exhaust manifold

308, the coolant demand and heat dissipation may be controlled separately from the first cooling space 304. The water inlet 310 into the second cooling space

309 in the region of the exhaust manifold 308 can be effected by separate Wassereintrittsöffnungen- from the outside or via the second inlet openings 311 in the fire deck 307. In the case of the latter embodiment shown in FIGS. 17 and 18, throttle openings may be provided in the cylinder head gasket, not shown, in the region of the second inlet openings 311 in order to permit additional coordination of the coolant quantity and an even distribution.

In the region of the coolant outlet 312 from the second cooling chamber 309, a thermostatic valve 313 or an electrical switching valve for controlling the additional cooling circuit through the second cooling chamber 309, in particular in the engine heating phase, may be provided before the confluence with the coolant circuit or the first cooling chamber 304 of the cylinder head 301 ,

Claims

PATENT CLAIMS

1. exhaust line (1) of an internal combustion engine, having at least one catalyst (2) with at least one in a housing (3) arranged catalyst carrier (4), which at least a first and a second parallel-flow area (5, 6), wherein means a switching device (8) arranged in the exhaust line (1), the flow being deactivatable by at least one region, characterized in that the regions (5, 6) of the catalyst carrier (4) have different physical and / or chemical properties with regard to the response, the permeability, have the catalytic activity and / or the thermal inertia.

Second exhaust line (1) according to claim 1, characterized in that the two regions (5, 6) have different cell densities.

3. exhaust line (1) according to claim 1 or 2, characterized in that the regions (5, 6) have different coatings.

4. exhaust line (1) according to one of claims 1 to 3, characterized in that the two regions (5, 6) are arranged coaxially with each other.

5. exhaust line (1) according to one of claims 1 to 3, characterized in that the two areas (5, 6) - viewed in the longitudinal direction of the catalyst (2) - are arranged side by side.

6. exhaust line (1) according to one of claims 1 to 5, characterized in that the two regions (5, 6) have different cross-sectional areas.

7. exhaust line (1) according to one of claims 1 to 6, characterized in that the catalyst carrier (4) is made in one piece and consists of a single monolith.

8. exhaust system (1) according to one of claims 1 to 7, characterized in that the switching device (8) by a switching flap (7) is formed.

9. exhaust line (1) according to one of claims 1 to 8, characterized in that the switching device (8) combined with the wastegate of the exhaust line (1) arranged exhaust gas turbocharger.

10. exhaust line (1) according to one of claims 1 to 9, characterized in that the switching device (8) in the exhaust gas flow downstream or upstream of the catalyst carrier (4) is arranged.

11. exhaust line (1) according to one of claims 1 to 10, characterized in that between the switching device (8) and the catalyst carrier (4) is arranged in the longitudinal direction of the flow-oriented partition (9), which the exhaust gas flow into a first to first area (5) and a second to the second area (6) leading flow path divides.

12. exhaust line (1) according to one of claims 1 to 11, characterized in that in the region of the switching device (8) and / or in the region of the partition (9) at least one leakage opening (10) is arranged, which deactivated a predefined amount of exhaust gas Area.

13. exhaust line (1) according to claim 12, characterized in that the leakage opening (10) by at least one opening, a corrugation or perforation of the partition wall (9), preferably in a subsequent to the catalyst carrier (4) wall area is formed.

14. exhaust line (101) of an internal combustion engine with at least one catalytic converter (102) having at least one in a housing (103) arranged catalyst carrier (104), which at least a first and a second parallel-flow area (105, 106), wherein by means of a in the exhaust line (101) arranged switching device (108) the flow through at least one region (105, 106) is deactivated, characterized in that in the region of the outlet (113) from the second region (106) of the catalyst carrier (104) a first flow deflection (Lilac) is arranged, which at least a portion of the exhaust gas emerging from the second region (106) by a first sector (105a) of the first region (105), so that the exhaust gas flows meandering through the catalytic converter (102).

15. Exhaust line (101) according to claim 14, characterized in that the regions (105, 106) of the catalyst carrier (104) have different physical and / or chemical properties with regard to the response, the permeability, the catalytic activity and / or the thermal inertia

16. exhaust line (101) according to claim 14 or 15, characterized in that in the region of the inlet (114) of the first region (105) of the catalyst carrier (104) has a second flow deflection (purple) for the There is arranged recirculated exhaust gas exiting from the first sector (105a) of the first region (105) from the catalyst carrier (105), which recirculates the recirculated exhaust gas to a second sector (105b) of the first region (105).

17. Exhaust line (101) according to any one of claims 14 to 16, characterized in that the first Strömungsumlenkeinrichtung (purple) by a first switching device (108 a) is formed, which is switchable between at least two positions, wherein in at least a first position of the Exhaust gas exiting the second region (106) of the catalyst carrier (104) can be traced in the direction of the first sector (105a) of the first region (105).

18, exhaust gas line (101) according to claim 17, characterized in that between the catalyst carrier (104) and said first switching means (108a) has a substantially longitudinal direction of the flow oriented first partition wall is arranged, one end (109a ¹⁾ of the partition ( 109a) is located downstream of the first region and defines the boundary between first and second sectors (105a, 105b) of the first region (105).

19. exhaust line (101) according to one of claims 14 to 18, characterized in that the second flow deflection (111b) by a second switching device (108b) is formed, which is switchable at least between two positions, wherein in at least a first position, the through the exhaust gas recirculated to the first sector (105a) of the first region (105) can be deflected in the direction of a second sector (105b) of the first region (105).

20. Exhaust line (101) according to claim 19, characterized in that between the second switching device (108b) and the catalyst carrier

(104) a substantially in the longitudinal direction of the flow-oriented partition wall (109b) is arranged, which - with the second switching means open (108b) - the exhaust gas flow in a first to the first region

(105) and a second flow path leading to the second region (106).

21. Exhaust line (101) according to one of claims 17 to 20, characterized in that the first and / or second switching device (108a, 108b) by a switching flap (107a, 107b) is formed.

22. Exhaust line (101) according to any one of claims 17 to 21, characterized in that the first and second switching means (108a, 108b) at the same time via at least one actuator (112) are actuated.

23. Exhaust line (101) according to one of claims 14 to 22, characterized in that the regions (105, 106) and / or sectors (105a, 105b) have different cell densities.

24. Exhaust line (101) according to any one of claims 14 to 23, characterized in that the regions (105, 106) and / or sectors (105a, 105b) have different coatings.

25. Exhaust line (101) according to any one of claims 14 to 24, characterized in that the regions (105, 106) and / or sectors (105a, 105b) are arranged coaxially with each other.

26. Exhaust line (101) according to one of claims 11 to 25, characterized in that the regions (105, 106) and / or sectors (105a, 105b) - viewed in the longitudinal direction of the catalytic converter (102) - are arranged side by side.

27. Exhaust line (101) according to one of claims 14 to 26, characterized in that the regions (105, 106) and / or sectors (105a, 105b) have different cross-sectional areas.

28. Exhaust line (101) according to one of claims 16 to 27, characterized in that the flow cross section of the second sector (105b) of the first region (105) is greater than or equal to the flow cross section of the first sector (105a).

29, exhaust line (101) according to any one of claims 14 to 28, characterized in that the catalyst carrier (104) is made in one piece and consists of individual monoliths.

30. An internal combustion engine (201) having an exhaust system with at least one water injection device (205) for injecting water into an exhaust line (203), characterized in that the water injection device (205) upstream of an exhaust aftertreatment device (207), preferably upstream of a turbine (204b) an exhaust gas turbocharger (204), in the exhaust line (203) opens.

31. Internal combustion engine (201) according to claim 30, characterized in that the water injection system (205) comprises a condensation system (210) for recovering water by dehumidifying air or exhaust gas.

32. Internal combustion engine (201) according to claim 31, characterized in that the condensation system (210) has an exhaust gas condensation device, which via an exhaust gas removal line (214) with the exhaust line (203) is connectable.

33. Internal combustion engine (201) according to claim 31 or 32, characterized in that the condensation system (210) comprises an air condensation device, wherein preferably the air condensation system is part of an air conditioner.

34. Internal combustion engine (201) according to one of claims 31 to 33, characterized in that the condensation system (210) comprises a condenser (210a) with filter and reservoir (211), in which the condensate inlet (212) of the exhaust gas condensing device and / or Condensation inlet (213) of an air condensation device, preferably an air conditioner, opens.

35. Internal combustion engine (201) according to any one of claims 32 to 34, characterized in that the exhaust gas removal line (214) branches off downstream of the exhaust gas aftertreatment device (207) from the exhaust line (203).

36. Internal combustion engine (201) according to claim 35, characterized in that the via the Abgasentnahmeleitung (214) branched off exhaust gas after passing the exhaust gas condensing device an intake manifold (202) of the internal combustion engine via a to the condensation system (210) subsequent exhaust gas recirculation line (214a, 214b) can be fed is, wherein preferably in the exhaust gas recirculation line (214 a, 214 b), a check valve (217) or a control valve (218) is arranged.

37. Internal combustion engine (201) according to claim 36, characterized in that the exhaust gas recirculation line (214b) opens into the intake line (202) upstream of a compressor (204a).

38. Internal combustion engine (201) according to any one of claims 30 to 37, characterized in that the water injection system (205) has a flow control device (209), which in the water injection system (205) downstream of a feed pump (208) is arranged.

39. Internal combustion engine (201) according to any one of claims 31 to 38, characterized in that the water injection system (205) has a frost protection device.

40. Cylinder head (301) for an internal combustion engine with liquid cooling and with a liquid-cooled exhaust manifold (308) formed integrally with the cylinder head (301), wherein the cylinder head (301) has at least a first cooling space (304), characterized in that the Area of the exhaust manifold is at least partially surrounded by a second cooling chamber (309) which is at least partially separated from the first cooling space (304), wherein preferably the coolant flow through the second cooling chamber (309) is separated from the coolant flow through the first cooling chamber (304) adjustable ,

41. Cylinder head (301) according to claim 40, characterized in that in the second cooling chamber (309) at least one preferably from the cylinder head dichtdichtf pool (307a) emanating outgoing separate coolant inlet (310), which fluidly connectable with a cooling jacket of the cylinder block is.

42. Cylinder head (301) according to claim 40 or 41, characterized in that the second cooling space (309) has at least one coolant outlet (312).

43. Cylinder head (301) according to claim 42, characterized in that the coolant outlet from the second cooling chamber (309) is connected to the first cooling space (304).

44. Cylinder head (301) according to any one of claims 40 to 43, characterized in that in the region of the coolant inlet (310) or the coolant outlet (312) at least one thermostatic valve (313) or a preferably electrical switching valve is arranged.

45. Cylinder head (301) according to one of claims 40 to 44, characterized in that in the region of the coolant inlet (310) in the second cooling chamber (309) at least one throttle opening is arranged, wherein preferably the throttle opening is formed by the cylinder head gasket.